Tensions were high Friday as hundreds of protesters clashed with police outside a hotel where Donald Trump spoke to members of California's Republican establishment.
Trump traveled to Silicon Valley, an area with a decidedly liberal population, a day after violence erupted at a campaign rally of his in conservative Orange County in Southern California.
More than 300 demonstrators swarmed outside the hotel near San Francisco airport, forcing Trump to crawl under a fence to enter the hotel. "That is not the easiest entrance I've ever made," he told the gathering. "It felt like I was crossing the border," he said, referring to migrants who often make similar maneuvers at America's southern border.
The protesters, some wearing bandannas over their faces and carrying Mexican flags, held signs protesting Trump's controversial plan to build a wall along the U.S.-Mexico border to prevent illegal immigration. They tried to rush the hotel entrance but were pushed back by police.
Protesters crowd the street after a rally for Republican presidential candidate Donald Trump, Thursday, April 28, 2016.
A day earlier, police arrested 17 people outside the Trump rally in Costa Mesa, south of Los Angeles. At one point, police in riot gear and on horseback formed a barrier between the two groups outside Orange County's Pacific Amphitheater, where Trump delivered a campaign speech. The windows of a police car were smashed and several people were injured before the crowd was brought under control.
Trump is closing in on the 1,237 delegates he needs to clinch the Republican presidential nomination after a string of dominant primary victories in states that included New York, Pennsylvania and Maryland.
His rivals, Texas Senator Ted Cruz and Ohio Governor John Kasich, have been mathematically eliminated from winning a first-ballot nomination. Their only hope is to deny Trump a majority of delegates heading into the July convention and wrestle for the prize in multiple ballots there.
The next key race is Tuesday, with Republican and Democratic party primaries in Indiana, a conservative Midwestern state with vast farmlands and industrial centers.
A win in Indiana for Trump would not lock up the nomination for him but would give him a significant edge as he heads to the final nine state nominating contests, which run through early June.